Mr Crowley :When you pull back on the lever that depresses the fuel canister and injects the fuel, does the fan also turn on and vent the chamber at the same time?►it's like that: i pull back the lever, that depress the fuel (régulated flow with a faucet), open the chamber valve, turn on the 9v fan to refuel the chamber.It's the same system on my gatling and my spas12.but in this version, the system is most compact.